The World of Duel Monsters
by Rin66
Summary: Tsuna and his Vongola family were transported to the world of Duel Monsters. As they gain new allies in Domino City, they learn about a mafia family that will cause chaos in both worlds. They must learn the ways of dueling and battle through cities while evil awaits them. Will Tsuna, his family, and his new friends be able to stop their plans of world domination?
1. Chapter 1

"Ugh... where am I...?"

Tsuna groaned as he got up. "Juudaime!" Gokudera ran up to Tsuna frantically. "Are you okay?!" "Y-yeah..." "Anyway, where are we?!" Tsuna looked around at his surroundings. All he saw were trees, plants, rocks, etc. "I-I guess we're in a forest..." _Snap!_ Gokudera turned around. "Who's there!?" He took out a few dynamites as his teeth gritted tightly on his cigarette. The bushes in front of him shook and a small dragon flew out. Gokudera was about to light his dynamites, but Tsuna stopped him. "Wait! It might be harmless!" "Che, how do you know?" Tsuna walked up to the black dragon and looked at it in the eyes. "...because its eyes don't show any intent of harming us. Anyway, if it would attack us, it would've done something by now." Gokudera sighed and put away his dynamites. "Hi there, little dragon. Do you know the way out of this forest?" Tsuna reached out to pet it. At first, the dragon hesitated, but as it stared at him, it sensed that he was a friend. It lowered his head and let him pet it. Gokudera watched Tsuna in amazement. "Wow... you should be a dragon tamer one day..." Tsuna gave him a nervous smile. "Uh... I don't think I can be one... anyway..." Tsuna turned back to the dragon. "Do you know the way out of this forest?" The dragon shook its head. "Do you know anyone that can lead the way out of this forest?" The dragon nodded and... purred? Well, at least it knew someone that can lead them out. Gokudera looked at the dragon suspiciously. "And why should we trust you? You might lead us to your cave and have your friends eat us!" The dragon snorted and started to fly away. "I don't think it would do something like that, so don't worry." Tsuna started jogging after it. Gokudera stood there for a while. Finally, he decided to trust the dragon and ran after them.

* * *

Yamamoto looked around and laughed. "Hahaha... I guess we're lost!" Ryohei pounded his fist on a tree. "How is that a good thing!?" Lambo jumped around. "Wow, what a fun playground!" He jumped onto a tree and started climbing. Yamamoto picked him off of the tree. "Maa maa... that's dangerous you know? You can fall off and hit your head~" Ryohei looked around in alert. "Hey... do you hear that?" Yamamoto's smile turned into a firm line of concern. "Hear what?" "Ssshhh... I hear footsteps..." Ryohei looked at the direction to where the footsteps are coming from and got into his fighting position. Yamamoto put down lambo and held onto the hilt of his katana, ready to draw it. Lambo hugged onto Yamamoto's leg in fear. As the sound of twigs and leaves were heard, a tall boy a little older than their age stepped out. He has blood-red eyes, silver hair that reached to his chin, a fringe covering his right eye, and a long ponytail that reached to his waist. He has a fair, smooth skin complexion, and he wore dark blue jeans with a black tank top. Ryohei kept his eyes on him. "Who are you?" The teenager scoffed. "I can ask you the same... what are you three doing here...? This is private property you know." Yamamoto let go of his katana. "Private property...?" "Yes. This is a privately owned forest, and how did you get here?" Ryohei unclenched his fists. "We don't know. We just found ourselves lost here when we woke up."

The boy sighed. "Where are you guys from?" "Namimori, Japan." "...I never heard of that place before." Yamamoto's eyes widened. "What..." "There isn't a place in Japan called Namimori." "But how would you know?" The boy gave him a sharp look. "Because this is Domino City, Japan." Lambo picked his nose. "Eh? What's that?" Ryohei looked at Yamamoto. "But I never heard of such place in Japan..." Silver-hair gave them a concerned look. "Come with me. Maybe we'll find out what happened and why we never heard of such places." He turned around and walked through the bushes. "Hey, Yamamoto... should we follow him?" Yamamoto started to walk. "We should... He would help us, and I trust his word." Ryohei punched his fists together. "ALL RIGHT! LET'S FOLLOW TO THE EXTREME!" He started to run after them while Lambo tailed behind.

* * *

Hibari glared at who was in front of him while Mukuro smirked at who was glaring at him. "Oya oya... no need to be so angry... I didn't even do anything~" Hibari scoffed. "Weren't you the one who took us here?" "...So what if I did?" "Tch." Hibari whipped out his tonfa and attacked Mukuro. "Oh?" Mukuro blocked the attack with his trident. "Seems as if we're gonna have a some fun~" "Hn." They continued to strike at each other and brought the fighting up the trees. After a while, both of them have cuts and bruises all over their bodies. "Ummm... excuse me..." Hibari and Mukuro turned to where the voice came from. "Who's there?!" A girl that looked a little younger than them stepped out from behind a tree. She has midnight blue eyes, straight, violet hair that reached down to her waist, and a fringe covering her left eye. She wore a skirt that matched the color of her eyes and a white blouse tucked into the skirt. "Excuse me... but what are you two doing here?" Hibari and Mukuro lowered their weapons. "Kufufu... we just woke up and happened to find ourselves here in this lovely forest..."

"...Really?" "Yes, really. Anyway, where are we in the world?" The girl studied Hibari and Mukuro intensely. "We are in Japan. Domino City, Japan." Hibari gave her a sharp look. "There is no such place as Domino City in Japan." She shrugged. "Well we're in it, so it exists. Where are you two from?" "We're from Namimori, Japan." She tilted her head at Hibari. "I never heard of a city in Japan called Namimori..." Hibari raised one of his tonfa and growled. "We are from that city and that is that." "And this is Domino City so just accept the truth." "Tch..." Mukuro tried to stop Hibari, but he wasn't quick enough. Hibari charged at the girl and hit her on the cheek. "You annoy me." She forced herself to not lose balance and gently touched where he hit her. Mukuro walked in between her and Hibari to prevent further damage. "How could you do that to a girl, Hibari?" Hibari gave no response while the girl turned around to hide her tears from the pain. "It's fine... anyway, you two need help right? Follow me..." Hibari scoffed. "I don't need help. I'm not a weak herbivore like you." The girl glanced at him and gave a small smile. "I'm an omnivore." She started walking down a small path of leaves, twigs, and branches. Mukuro nudged Hibari. "Come on. Let's go." "...no." "Kufufu... don't give me a hard time now..." "Me? Give you a hard time?" "Hurry up! Let's just follow! Aren't you curious about what happened and why we're here?!" Hibari thought about that for a moment. "...fine." He started to walk after the girl while Mukuro walked behind him.

* * *

**This is my very first cross-over ^w^ I'm very excited about this one and I'll be updating shortly with the second chapter~!**


	2. Chapter 2

The little dragon led Tsuna and Gokudera through a path of bushes and plants. As it flew, it sniffed and looked around cautiously. Suddenly, it stopped and roared. A huge blue lizard jumped out of the bushes in front of them, its eyes wild with hunger. "HIIIIEEEEE W-WHAT IN THE WORLD IS THAT?!" The little black dragon blew a stream of fire at the lizard, but it caused no damage. "JUUDAIME! WATCH OUT!" The lizard snorted and ran at them with its jaws wide open. Tsuna and Gokudera jumped aside while the dragon flew up. As the lizard passed under it, something caught its eye. It swooped down onto the ground and ate something. "Hey! This isn't a time to be eating you know!?" Gokudera lit some dynamites and threw it at the lizard. The dynamites exploded, but as the smoke disappeared, the lizard still stood there, unharmed. "W-what in the world..." _ROOOOOAAAAR! _A loud roar resonated through the forest. The once small black dragon became a huge dragon. Its skin a shining obsidian black, its eyes glowing with the color of blood. Now that its size rivals the lizard's, the lizard started to cower in fear. The dragon inhaled deeply and exhaled a burst of flames from its mouth, bathing the lizard in fire. The lizard gave on last screech and exploded into pieces that disappeared once they hit the ground. Gokudera and Tsuna walked over to the dragon hesitantly. The dragon shrinked back to its original size and snorted in victory. Tsuna smiled and pet it. "Thank you for saving us..." Gokudera huffed in jealousy. "Shouldn't we be going somewhere now?" The dragon smirked at him and went back to leading the way.

* * *

"By the way, what are your names?" The boy looked at Ryohei, Yamamoto, and Lambo. "My name is Sasagawa Ryohei!" "I'm Yamamoto Takeshi!" "Ore, Lambo!" The boy smiled at them. "It's a pleasure to meet you, I'm Yoake Akatsuki. Just call me Akatsuki." Ryohei looked around. "Anyway, where are you taking us?" "You'll s-" Everyone stopped as they heard a loud roar. Lambo squealed. "W-what was that!?" Yamamoto's face turned serious while Ryohei was ready for battle. The boy seemed to be completely calm. "Calm down everyone... it was probably just my pet..." "WHAT KIND OF PET ROARS LIKE THAT TO THE EXTREME!?" The boy sighed. "And what kind of person yells like that? Come on, let's just continue walking..." The boy turned around and continued to walk through the path they were on.

* * *

"Kufufu... what was that?" Mukuro, Hibari, and the girl were looking around in alert as they heard a roar. "I-it was probably nothing..." "Hn, what do you mean 'nothing'? Of course it has to be something if it roars like that." "Come on... let's just hur...ry..." She stood there as her eyes widened with fear. A giant gray rat stood several feet in front of her. Hibari and Mukuro held up their weapons as they stared at it in disbelief. "What the heck is that...?" The girl reached under her skirt and took out a card. "Physical attacks won't do anything to these... and this wasn't even supposed to be here..." "Oh? and what do you mean by that?" The girl ignored his question and called out. "I summon you, Thunder Dragon!" A circle, with the word light, appeared on the floor in front of her and a green dragon materialized on it. Sparks of electricity coated its shining green scales as it growled. The rat sneered at the dragon and attacked it, but the dragon was a lot faster. It opened its mouth and blasted a beam of thunderbolts at it, electricuting and destroying the rat. Hibari and Mukuro stood there in interest as the dragon nodded at the girl before disappearing. "Kufufu... why thank you, er..." "Shiroitsuki. Yaoke Shiroitsuki. And yours?" The pineapplehead smiled. "What a name you have there... my name is Rokudo Mukuro and that's Hibari Kyoya~" "Hn." Shiroitsuki nodded at them. "Well... we should get going now before anything else gets to us..." She continued to walk up the path as Hibari and Mukuro followed her.


End file.
